I have never been a proponent of allowing cats to roam outside. Just as we keep our dogs either in a fenced yard or on a leash, cats should be protected from injury and disease by their owners. Since it is hard to keep a cat in the yard (although I do know a couple of people who have installed special fencing for this purpose), I keep my cats in the house all the time.
There are a number of feral cat colonies in Wichita Falls and generally the attitude is to leave them be. Recently, the city has moved to licensing feral cat colonies, which involved insuring the cats are captured, spayed/neutered, and given shots. Although this is a humane way to gradually reduce the colony, providing enough cats can be caught and sterilized, there are still a lot of environmental consequences to groups of feral cats, not to mention most of these cats are diseased and don't get enough to eat. For those who feed feral cats, get a pet cat and keep it in instead of encouraging the survival/increase of the feral cat population.
Recently, the University of Nebraska released a report on the impact of feral cats--it's not a pretty picture. Although portions of the report discuss Nebraska laws and regulations, most of the report is applicable to other areas as well. The portion of the report concerning control of feral cats will certainly be disturbing to many of my pet-loving friends, just as euthanasia of unwanted pets is offensive. All I can say is that we need to change the attitude of our society toward pets and animals overall.
I think cats are the perfect pet, but responsible pet ownership is key.